Inkjet and other printing processes have been used in many fields to manufacture products. For example, inkjet printing processes have been used in the manufacture of LCD and semiconductor products. See, e.g., U.S. Reissue Pat. No. 37,682, which although it involves an unrelated technical field is incorporated by reference herein in its entirety.
In addition, printing processes (such as screen printing and low temperature casting techniques) have been the subject of consideration for the manufacture of other medical (non-implant medical devices or non-self-containing drug implants) products. See, e.g., “Printing Evolves: An Inkjet For Living Tissue,” published in the Wall Street Journal on Sep. 18, 2012 at pages D1 and D3; and the Axxia patents/applications.
Further, non-printing methods have been used to create medical implant products, via conventional methods. These non-printing methods include, inter alia, hot-melt casting, extrusion, shrink-wrap and solvent based processes.
While some prior art processes have commercial advantages and they can be used as a part of the invention herein, it is the inventors' opinion that these prior art processes alone (i.e., when used without at least one 3-D printing process step) fail to satisfy at least one or more of the advantages that the present 3-D printing invention seeks to provide for controlled release subcutaneous medical implant devices. For example, a partial listing of the advantages that may result from the present 3-D printing invention are believed to include at least some of the following: The structure of the non-drug portions of the implant product may be designed and controlled rather precisely due to (i) the small, precise amounts of material deposited by each 3-D nozzle and (ii) the very thin or ultra-thin layer-by-layer building method of 3-D printing; and                1. The drug release pattern of the implants may be precisely regulated by the use of the 3-D nozzles to create the product on a layer-by-layer basis for the same reasons; and        2. The shape and configuration of the implant may be modified as desired by, for example, using the 3-D printing nozzles to deposit non-permanent materials that may be readily removed by etching, laser, mechanical, chemical or other known means; and        3. The present invention may avoid irregularities resulting from cutting or otherwise modifying extruded materials; and        4. The present invention may sometimes avoid the separate step of loading a drug material within the implant because, for example, the precise ratio of the drug material and the non-drug material in the matrix core can be precisely regulated and the release path and release rate of the drug materials within the matrix core to the opening in the implant device can be precisely designed; and        5. The present invention may provide great flexibility in the choice and use of both drug materials and non-drug materials, whereas, for example, certain previously known processes limit the commercial choice of plastic/thermoplastic/drug materials; and        6. Large numbers of implants may be created at one time and/or quickly so that, e.g., the overall yield is increased; and        7. The present invention may provide improved bonding/adhesion between the drug containing matrix and other portions of the implant (e.g. the coating); and        8. High manufacturing yield may be achieved—e.g., approaching as high as about 90-95%. Thus, for example, with hydromorphone costs of approximately $12,000/kg, this may be an important competitive advantage, especially in developing world markets.However, it should be understood that the present invention does not require that all of these advantages be achieved in every process covered by the scope and spirit of the invention.        